1. Field of Invention
The present invention is generally related to levels that include level vials and the manufacturing of such levels.
2. Description of Related Art
Level vials have been mounted to level frames, either directly or via a vial holder, by a variety of techniques. Fasteners, such as screws, have been used to attach vial holders carrying the level vials to wooden or metal frames. It is also common to attach level vials and their holders to the level frames with adhesives.
During a typical assembly of a level, the level vial is adjusted in its holder while the level is positioned on a known level surface. When the level vial has been adjusted to the correct position, as indicated by the bubble contained therein, the level vial is glued in place. The vial holder may also be glued in place. The order in which the attachment occurs may vary. For example, the level vial may be attached to the vial holder first, then the vial holder may be adjusted and attached to the level frame, or the vial holder may be attached to the frame first, then the level vial may be attached to the vial holder. The amount of adhesive that may be used to glue the vial holder in place in the frame may vary greatly. Nothing prevents an excess amount of adhesive from being applied, and upon application, the adhesive may freely flow within the frame. However, if too little adhesive is applied, there is a risk that the adhesive bond between the vial holder and the frame may fail over time. Therefore, to err on the side of caution, excess adhesive is typically applied, which creates an additional cost to manufacture the level.
In addition, typical levels also include plumb and/or 45° vial stations that are located near the ends of the level. Levels that have frames of a hollow construction have the plumb vial stations located near the ends of the level, because during assembly, the plumb vial stations are inserted into the frame through the openings at each the end of the frame.
It is desirable decrease the cost to manufacture levels, yet still provide a durable, highly accurate level, both with horizontal and vertical (plumb) vials.